Pump and cushioning device therefor



Patented Mar. 27, 1934 UNITED STATES PATENT OFFICE 2 Claims.

My invention relates to new and useful improvements in metering pumpsfor the pumping of viscose, nitrocellulous collodion, acetate,cuprammonium, or other similar fluids used in the manufacture of rayon,artificial straw, and other goods having the same base as rayon.

Still another object of the invention is to provide a cushioning deviceand known in the trade as a pressure bottle with the pump to obtain acushioning effect to absorb the pulsations al- Ways presented when apiston pump is used.

Y Still another object of the invention is to provide a new and novelform of cushioning device to absorb or cushion the pulsations that arecommon in the various forms of pumps, the present device beingespecially adapted for use with the types of pumps shown in Patents Nos.1,783,439, on Pumping unit for artificial silk spinning machines,granted December 2, 1930, 1,785,355, on 20 l Spinning pump, grantedDecember 16, 1930, and 1,785,356, on Spinning pump, granted December 16,1930.

Still another object of the invention is to provide a relativelynon-breakable cushioning device known in the trade as a bottle in whichthere is either a fixed diaphragm or a floating means that iscompressible so as to absorb or cushion the pulsations of the pump tothus produce a steady flow of the liquid from the pump to 30 thespinneret or spinning jet.

It has been the former practice with a pump of the type shown in theabove-mentioned patents to provide a glass cushioning device that istightly but detachabl'y held over an inlet and an outlet, so that theliquid passes from a port up into this cushioning device, where thepulsations are absorbed or cushioned by the air in the cushioning devicebefore the liquid passes to the spinneret and is solidified into athread.

Still another object of the invention, therefore, is to provide acushioning device that is preferably made of metal, but mightbe made ofbakelite, hard rubber, or similar substances.

Still another object of the invention is to provide a pump with 'acushioning device which is preferably made of metal and in which thereis located a diaphragm behind which the air is entrapped, so that whenpressure is built up in the cushioning device, the diaphragm and eventhe air behind it will be compressed to thus absorb and cushion thepulsations of the, liquid flowing into the cushioning device and thuscause the liquid to be delivered in a steady stream from the outlet portof the cushioning device to the spinneret.

Still another object of the invention is to provide a pump with acushioning device wherein a floating form of diaphragm might be used,such as a ball made of relatively thin metal, celluloid, etc. so thatthe pressure in the bottle will cause the ball to compress and againexpand as the back pressure in the cushioning device is equalized tosimilarly allow a steady jet or fiow from the pump. With these and otherobjects in view, the invention consists in certain new and novelarrangements and combination of parts, as will be hereinafter more fullydescribed and pointed out in the claims.

In the drawing,

Fig. 1 is a transverse sectional view of a wellknown type of meteringpump with the new form of cushioning device attached;

Fig. 2 shows the separate parts of the cushioning device before beingassembled;

Fig. 3 is a central sectional view of the pump to show the arrangementof the ports;

Fig. 4 shows a slightly modified form of cushioning device.

Referring now to the drawing, it will be seen that Fig. 1 shows ametering pump of the type shown in Patents Nos. 1,783,439, on Pumpingunit for artificial silk spinning machines, granted December 2, 1930,1,785,355, on Spinning pump, granted December 16, 1930, and 1,785,356,on Spinning pump, granted December 16, 1930, consisting of thecylinder-1, the rotor 2 with the bores 2', in which are mounted thepiston plungers 3, which plungers, in turn, are provided with the balls4 on their ends, which balls fit in chambers 5 in the angularly placedrotor cam 6. This rotor cam 6 bears against the stationary cam face 7 ofthe back piece 8. On the opposite end of the rotor is the stem 9extending through the head 10, while on the outer end of the stem 9 isthe gear 11. The rotor has a central bore 12 in which is fitted a spring13, which spring, in turn, bears against the head 14 of the stem 15which, in turn, bears against the ball 16, which ball is centrallylocated in a depression 17 in the rotor cam 6. There may be seen themain inlet port 18 which communicates with a circumferential groove 19formed in the casing. This groove 19, in turn, communicates at timeswith the cylinders 2 through the ports 2 During the suction stroke ofthe pistons, therefore, the fluid is drawn into the cylinders 2' throughthe ports 2 and as the rotor revolves, the liquid is then, by thecompression stroke of the pistons, forced over into asecondcircumferential groove 19' through the rotor. From this secondcircumferential groove, the liquid is forced up through the opening 22formed in the top of the casing (over which is fitted a pressure bottle,shortly to be described) Another opening 23 may be seen at the top ofthe casing, in which is fitted the small tube 24, this tube and openingcommunicating with a further circumferential groove 23, whichcommunicates with the main outlet of the pump 21.

As far as the specification has proceeded, the pump is identical withthe pump shown in the above-mentioned patents, with the exception thatthe little tube 24 is placed in the opening 23 (which in this case isthe outlet) rather than in the opening 22, as shown in the patentsabovementioned.

The arrangement and description of the grooves and the ports, as well asthe glass type of cushioning device, or as known in the trade aspressure bottle, are specifically pointed. out in one of theabove-mentioned patents, to wit: 1,783,439, on Pumping unit forartificial silk spinning machines, granted December 2, 1.930, and it isnot thought necessary in this application to go into a full discussionof the pump per se.

. It is necessary to have what is known in the trade as a (pressurebottle, asin the pumping of viscose, nitrocellulous collodion, etc., theuniformity of the thread depends entirely upon the uniformity of thedelivery of the metering pump and it is, therefore, essential that acushioning device, known in the trade as a pressure bottle," be used toabsorb the pulsations caused by the pistons of the pump.

It will be understood that, the liquid flows up into the pressure bottleand thence out through the outlet to a spinneret or spinning jet (notshown) which is, in reality, a small die with a quantity of minute holestherein and which is submerged in a precipitated bath of differentchemicals used to coagulate the liquid into a solid thread, Since theliquid being pumped is usually of a high viscosity, a back pressure ofvarying degrees is built up when its free passage is obstructed by theaforementioned spinning jet. This back pressure causes the surface ofthe liquid in the cushioning device to rise until the entrapped air iscompressed to a pressure equal to the back pressure caused by thespinning jet. The impulses caused by the separate plungers causedefinite fluctuations in the discharge pressure and the air which isentrapped under pressure in the top of the cushioning device acts as acushion and absorbs the pulsations in such a way that they do not passon with the fiow of liquid to the spinning jet.

Now heretofore, the so-called bottles were formed of glass and as theliquids cannot be in contact with air for any great length of timewithout beginning to solidify, that part of the liquid which was indirect contact with the air in the top of the bottle and which does nothave as complete a circulation as that in the bottom of the bottlestarts to change into a semi-solid mass, making it necessary to removethe bottles from the pump at frequent intervals to remove the mass andto clean out any of the stagnant or partly solidified fluid.

Thus, when the pumps are used by the thousands, there is a relativelylarge loss of time in the removal and cleaning of the bottles.Furthermore, the bottles when made of glass were often broken, due to'carelessnesson the part of further aligning ports 2 that are formed inthe" operators, back pressure in the bottles, and im'- perfect bottles.

Now referring to the gist of the invention, there will be seen what isknown as a pressure bottle 25 that is a cushioning device, and in thepresent instance it is preferably formed of metal, although a cushioningdevice formed of hard rubber or bakelite might be used. It will benoticed that this cushioning device 25 is threaded at its lower end, asat 26, to removably fit within the threaded portion 27 of the lug 7Resting on top of the cushioning device 25 or fitted therein is thecompressible tempered convex steel diaphragm 28, while over this, inturn, is tightly screwed the cover 29. It will be noticed that there isan air space 30 provided between the diaphragm 28 and the top of thecover 29.

In the present instance and, as shown in Fig. 1, rather than entrappingthe air in the cushioning device, the inlet and outlet ports have beenchanged from the pump shown in the previous patents and thetube 24 isplaced in the outlet port instead of the inlet port to thus expel theair rather than trap it.

The impulses then, instead of being absorbed 100 by the air cushion, asin the former style, are absorbed by the tempered steel diaphragm 28 andfurther by the air cushion 30 behind the steel diaphragm. In otherwords, when the cushioning device has become completely filledwith theliquid 105 (not shown) the back pressure forces the concave temperedsteel diaphragm to rise until its resistance is equal to the backpressure caused by the liquid being retarded in the spinneret orspinning jet. Thus, as the pulsations occur in the delivery of theliquid to the cushioning device, the diaphragm will rise and fall ateach impulse to cause a cushioning effect. There is alsoan addedcushioning efiect, however, due to the air en trapped behindthediaphragmor inthe ball, so that the pulsations are really absorbed or cushe,ioned by both the diaphragm and the air that is compressed behind thediaphragm, or in the ball, ifthe modified form is used.

In Fig. 4, I have shown a cushioning device 31 120 with its cover 32,but rather than having a fixed diaphragm therein, there is placed acompressible sealed ball33, that mi ht be made of tempered steel orother thin metal or, infact, might be made of relatively thickcelluloid, rubber, fiber, or any other composition that will allow thesides or surface of the ball to be compressed by the fluctuatingpressure in thecushioning device to thus absorb the pulsations.

From the foregoin it will be seen that by forming a cushioning device ofmetal with a. compressible diaphragm therein, I have dispensed with theordinary glass bottle, thus overcom,-. ing what amounts to a seriousloss of time caused by the breakage of the bottles, andfurthermore, haveprovided a cushion n device that will not neednearthe cleaningthat theglass bottle, does. Again, rather than entrapping the air, the air isexpelled from the cushioning device, while the pulsations of the liquidin the cushion 140 ing device are absorbed or cushioned by the diaphragmand the cushion effect furtherassisted by the air. entrapped behind thediaphragm.

In actual use, I have found that the cushioning device remains clean andthatthe discharge of the viscose from the cushioning device is in a fineand even stream, free of pulsations, which results in a uniformity ofdelivery to thus cause a uniform thread.-

It will be understood that this cushioning do, 150

vice might be readily adapted for use with other forms of pump besidesthat shown, as it may be easily fitted by simply cutting a receivingthread in the casing over openings that are present in any form of pump,where the glass type cushioning device is used.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:-

1. In combination with a rotary reciprocating type metering pump, thecasing of the pump provided with an inlet, a port connected with theinlet and pistons cooperating with said port to force the fluid underpressure into a cushioning device, said cushioning device including anair chamber having a flexible diaphragm therein, the pump also providedwith an outlet port, a pipe within the cushioning device, its upper endadjacent said flexible diaphragm and connected at its lower end to saidoutlet port whereby fluid under pressure will pass from said cushioningdevice and pump in a steady stream rather than with a pulsating efiect.

2. In combination with a rotary reciprocating type metering pump, thecasing of the pump provided with an inlet, a port connected with theinlet and pistons cooperating with the port to drive the liquid throughsaid port, a cushioning device, said cushioning device including an airchamber having a flexible diaphragm therein, a pipe within thecushioning device its upper end adjacent said flexible diaphragm, thefluid under pressure being driven through said port and into saidcushioning device, the lower end of the pipe of the cushioning deviceconstituting an outlet from the cushioning device whereby the fluidunder pressure will pass from the pump into the cushioning device andthen from said cushioning device in a steady stream rather than with apulsating effect.

JOSEPH PAUL LAIRD.

